392 Critical Care October 2003 Vol 7 No 5 Cabestrero et al. Oxytocin is frequently used worldwide. Some of its adverse effects are well known, but bronchospasm and laryngeal stridor as anaphylactoid reactions have not yet been reported. Oxytocin is a synthetically prepared hormone that stimulates contractions of uterine smooth muscle and it is used for induction and augmentation of labor as well as in abortions. Adverse effects reported with oxytocin include reflex tachycardia, hypotension, electrocardiographic changes, increased cardiac output, myocardial infarction, alteration in fetal heart rate, seizures, headache, memory impairment, cerebrospinal bleeding, hyponatremia, syndrome of inappropriate antidiuretic hormone secretion, nausea and vomiting, uterine rupture, neonatal hyperbilirubinemia, and anaphylaxis [1]. To our knowledge, bronchospasm and laryngeal stridor occur very rarely in oxytocin anaphylaxis. A 41-year-old woman was admitted to our intensive care unit after having a septic abortion in the 18th week of pregnancy. This was her second gestation (the first culminating in a cesarean section). After abortion she presented with septic shock, oligoanuria, consumption coagulopathy, and respiratory insufficiency. She was first treated intravenously with crystalloids, colloids, inotropics, furosemide perfusion, empirical antibiotics (i.e. cefotaxime, metronidazol, and doxycycline), and frozen fresh plasma. She was anticoagulated with low-molecular-weight heparin. She also received an intravenous infusion of oxytocin at 40 mU/min. Just after infusion, she showed signs of tachypnea, bronchospasm, and laryngeal stridor. We immediately started treatment with β 2 agonist drugs. Thirty minutes later the patient showed slight improvement, but symptoms only disappeared when oxytocin was withdrawn. The patient’s condition improved rapidly and recovery was uneventful. She had had no previous allergic reactions or asthma. Anaphylactoid reactions to oxytocin have been described in the literature [2]. Some of the clinical presentations of oxytocin anaphylactoid reactions described include patchy erythema, hypotension, bronchospasm, and reduced oxygen saturation [3,4]. A case of life-threatening respiratory distress following the use of oxytocin during cesarean delivery was reported in 1994; the authors of that report also suggested that this was an anaphylactoid reaction to synthetic oxytocin [5]. In the case described here, the close temporal relationship between oxytocin administration and bronchospasm and laryngeal stridor, and the rapid abatement of symptoms following oxytocin withdrawal suggest that the relation was a causal one and that the patient had suffered an anaphylactoid reaction. Competing interests None declared. References 1. Batagol R, Drugdex Editorial Staff: Oxytocin: drug evaluation. In Drugdex Information System, vol 104. Englewood, CO: Micromedex Inc.; 2000. 2. Spears FD, Liu DWH: Anaphylactoid reaction to syntocinon? Anaesthesia 1994, 49:550-551. 3. Slater RM, Bowles BJM, Pumphrey RSM: Anaphylactoid reac- tion to oxytocin in pregnancy. Anaesthesia 1985, 40:655-656. 4. Emmott RS: Recurrent anaphylactoid reaction during cae- sarean section [letter]. Anaesthesia 1990, 45:62. 5. Morriss WW, Lavies NG, Anderson SK, Southgate HJ: Acute res- piratory distress during caesarean section under spinal anaesthesia. A probable case of anaphylactoid reaction to Syntocinon. Anaesthesia 1994, 49:41-43. Letter Bronchospasm and laryngeal stridor as an adverse effect of oxytocin treatment David Cabestrero 1 , Carmen Pérez-Paredes 1 , Ramón Fernández-Cid 2 and Miguel A Arribas 1 1 Staff Specialist, Critical Care Unit, Hospital Verge del Toro, Mahón (Menorca), Spain 2 Director of Intensive Care, Critical Care Unit, Hospital Verge del Toro, Mahón (Menorca), Spain Correspondence: David Cabestrero, cabestrero@saludalia.com Published online: 10 July 2003 Critical Care 2003, 7:392 (DOI 10.1186/cc2348) This article is online at http://ccforum.com/content/7/5/392 © 2003 BioMed Central Ltd (Print ISSN 1364-8535; Online ISSN 1466-609X) . was an anaphylactoid reaction to synthetic oxytocin [5]. In the case described here, the close temporal relationship between oxytocin administration and bronchospasm and laryngeal stridor, and. et al. Oxytocin is frequently used worldwide. Some of its adverse effects are well known, but bronchospasm and laryngeal stridor as anaphylactoid reactions have not yet been reported. Oxytocin. and laryngeal stridor occur very rarely in oxytocin anaphylaxis. A 41-year-old woman was admitted to our intensive care unit after having a septic abortion in the 18th week of pregnancy. This was